dictA = {
  'name': 'Alex',
  'age': 18,
  'weight': '55kg'
}

# 增
dictA['nickName'] = 'DouDou'
print(dictA)
# {'name': 'Alex', 'age': 18, 'weight': '55kg', 'nickName': 'DouDou'}

# 删
del dictA['weight']
print(dictA)
# {'name': 'Alex', 'age': 18, 'nickName': 'DouDou'}

# 改
dictA['weight'] = '57kg'
print(dictA)
# {'name': 'Alex', 'age': 18, 'nickName': 'DouDou', 'weight': '57kg'}

# 查 / 取值
item = dictA['name']
print(item)
# Alex
has = 'name' in dictA
print(has)
# True
